Studies of galactolipid metabolism in Dunaliella salina

Thesis/Dissertation · Thu Jan 01 04:00:00 EST 1987

OSTI ID:7140589

Cho, S H

The metabolic interrelationships between monogalactosyldiacylglycerol (MGDG) and digalactosyldiacylglycerol (DGDG), the two major lipid components of chloroplast membranes, of Dunaliella salina were studied though the use of combined techniques of radioactive labeling and high performance liquid chromatography. Cells were pulse labeled with (/sup 14/C)- or (/sup 3/H)- fatty acids, and individual molecular species were analyzed for their specific radioactivity. MGDG was initially made in the form of 18:1/16:0, the most saturated molecular species. This was then either rapidly desaturated to 18:1/16:1 MGDG or galactosylated to 18:1/16:0 DGDG. 18:1/16:1 MGDG was subject to rapid further desaturation, ultimately to 18:3/16:4 MGDG, the most unsaturated molecular species present. Galactosylation favored MGDG molecular species having both fatty acyl chains unsaturated. 18:3/16:0 DGDG was made by a separate path involving the sequential desaturation of 18:1/16:0 DGDG. Thus, contrary to widely held opinion, desaturation occurs on fatty acids bound to DGDG as well as MGDG.

• Research Organization: Texas Univ., Austin (USA)
• OSTI ID: 7140589
• Country of Publication: United States
• Language: English

Related Subjects

550501* -- Metabolism-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ALGAE
CARBON 14 COMPOUNDS
CARBOXYLIC ACIDS
CELL CONSTITUENTS
CHLOROPLASTS
CHROMATOGRAPHY
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
LIPIDS
LIQUID COLUMN CHROMATOGRAPHY
MEMBRANE PROTEINS
MEMBRANES
METABOLISM
ORGANIC ACIDS
ORGANIC COMPOUNDS
PHOTOSYNTHETIC MEMBRANES
PLANTS
PROTEINS
SEPARATION PROCESSES
TRACER TECHNIQUES
TRITIUM COMPOUNDS